The subject of the present invention is a rolling bearing with two rows of rolling elements, of the type comprising a first ring formed in one piece and having two raceways and a set of two independent rings, each having one raceway.
One of the problems to be solved in rolling bearings of this type is to connect or fix together the two independent rings axially during the operations of handling, transporting, assembling and, if appropriate, dismantling the rolling bearing in the mechanical assembly in which it is incorporated when it is operating normally.
Such means of fixing the independent rings of bearings axially together have already been provided. Thus, for example, in French Pat. No. 2,439,902 a plsatic bush fitted into the bore in the two independent rings, here forming the inner rings, is used. This makes the connection between the two inner independent rings during the handling and transport operations, up to the moment when the rolling bearing is mounted in the mechanical assembly with which it is to interact. However, the disadvantage of such a means of axial fixing is that this plastic bush has to be ejected before the inner rings are fitted onto the shaft. When the plastic bush is removed in this way, the inner rings are no longer retained and then risk coming apart, with all the risks which that entails (tangling, damage, pollution, the risk of loss of the rolling elements). The same disadvantages arise if the rolling bearing is dismantled outside its receptacle.
Moreover, if such an axial fixing bush fitted in the bore of the inner rings is left in position, this results in inadmissible marking and damage of the shaft. The same can be said regarding, for example, the use of a bush which grips the two independent inner rings in French Pat. No. 2,078,551. The crimping of a metal bush is a solution which is complicated to put into practice. Moreover, it gives rise to a poor-quality bearing surface on the shaft.
Another solution involving crimping a metal collar or stud on the outer surface of two independent outer rings is described in French Pat. No. 2,104,411. Although the connection made in this way is relatively effective, it is nevertheless still difficult and costly to carry out.
French Pat. No. 2,439,902 already mentioned also envisages using, as means for the axial retention of the two independent inner rings, elastic collars or flanges fixed axially to the outer ring. The axial connection between the independent inner rings is made as a result of the interaction of these attached elements with the rolling elements and by means of suitable steps fashioned in the inner rings. Quite apart from the complexity of such means, it can be seen that it is inadvisable to transmit forces via the interior of rolling elements which do not rotate before assembly, since that presents considerable risk of damage, particularly if the rolling elements come in contact with the flanges, retaining rings or elastic collars which ensure that the two independent rings are fixed axially to one another.
French Pat. No. 2,489,905 also makes known a device for fixing two independent inner rings to one another by means of an elastic collar which snaps into grooves provided for this purpose in the two independent inner rings. However, this solution makes use of an attached accessory which has to be produced separately and the fitting of which requires relatively complex special precautions and operations.
Finally, French Pat. No. 2,492,919 describes a means of fixing together axially two independent inner rings of a ball bearing with two rows of balls by means of tongues integral with the bearing box, these tongues interacting with grooves specially made in the two independent rings. Despite the apparent advantages of such a means which does not have an additional piece separate from the box, such a device nevertheless presents inadmissible risks, particularly the risk of friction of the retention tongues of the box on the walls of the snap-in grooves of the two independent rings during the operation of the bearing.